Reader 9
eMacs running 10.4.x, latest updates
iMac dual core Intel running 10.5.x, latest updates
High school lab, with parental access turned on for students, Acrobat allowed.
Whenever I try to open it as a student, a window comes up asking:
Type an administrators name and password to make changes to Adobe Reader.

If I click on Details it says:
"Requested right: system.privilege.admin
Application: Adobe reader"

If I click Cancel on the approval screen, Acrobat opens and appears to work fine. It is a bit of a pain with 2500 students.